Mix up Marcel's production about a follower (8)
I believe the answer is:
scramble
'mix up' is the definition.
(thesaurus)
'marcel's production about a follower' is the wordplay.
'production' indicates anagramming the letters.
'about' indicates putting letters inside.
'a follower' becomes 'b' ('b' is the follower of 'a' in the alphabet).
'marcels' with letters rearranged gives 'scramle'.
'scramle' enclosing 'b' is 'SCRAMBLE'.
(Other definitions for scramble that I've seen before include "Climb awkwardly -- move quickly" , "Disorderly rush" , "Cycle event" , "race over rough terrain" , "Struggle" .)